“The greatest danger is that the sinner may sink to a level from which he can no longer raise himself.
Sometimes an accidental and quite trivial occurrence can cause a person to abandon an entire hallowed way of life.
Then, out of oversensitivity about the fallen state, he may continue for years to live in sin.
The seriousness of individual lapses should not be minimized, but neither should even the worst of them be allowed to lead to despair and total abdication.
“The righteous man may fall down seven times and yet arise” (Proverbs 24:16) describes the real-life experience of one who stumbles from time to time along the way, yet, no matter how painful the fall, always picks himself up, mends what can be mended, and moves on.
One who persuades himself that his very vulnerability to failure is a sign that he was never serious or sincere to begin with has rationalized a fatal descent.”
From “Lapses and Crises” in Teshuvah, p. 37, by Rabbi Adin Steinsaltz